The present invention is directed to an inflatable device suitable for the treatment or prevention of a congenital defect, congenital dislocation or dysplasia of the hip joint, in both diagnosed and undiagnosed cases, immediately or shortly after birth.
There is some confusion in the use of these terms, since dysplasia means only a dislocatable hip joint, and a distinction is important when considering the incidence of the defect. On the average, according to some authorities, the incidence of dysplasia seems to be about one percent of live births, but the fully developed cases of dislocated hips are considerably less frequent. This lends some authorities to the conclusion that there is a possibility of spontaneous stabilization of dysplastic hips in early infancy, even when not treated.
In any case, where there is only mild dysplasia it is not always diagnosed even by trained personnel, especially during early infancy. Therefore, it is possible that a number of cases may go undetected until the child is two or three months old, when X-ray examination will provide conclusive proof of whether there is a dysplasia/dislocation or not. The presence of such abnormalities calls for treatment by immobilization with appropriate splints, usually keeping the legs abducted at approximately 60.degree. and appropriately flexed. This posture which allows the head of the femur to exert pressure on the acetabulum (socket) has been proven to enhance good development as well as stabilization of the hip joint.
An adducted position of the thighs in infancy may lead to a higher incidence of dysplastic, respectively dislocated hips. This is supported by observations of such a higher incidence in populations where it is customary to swaddle infants with thighs in an adducted position. The importance of holding the thighs in an abducted position is now well recognized, and the present widespread practice is to use a makeshift arrangement, i.e., to use two, or perhaps more, layers of diapers, providing some semi-rigidity and also a kind of wad in the region of the groin to achieve abduction. However, this practice is only partially effective as the material of the diapers is water absorbent and loses almost all rigidity and resistance on becoming wet. Furthermore, it involves additional work, expense, and inconvenience.
Splints are used in the therapeutical treatment of diagnosed cases, but these are very rigid splints which tend to bruise the delicate skin of an infant. The use of foamed plastic cushions, trapped to the thighs and permitting certain freedom of adductive movements but capable of recovering their shape, has also been recommended in the literature.